Test instruments are known in the prior art which typically receive a signal, for instance a radio frequency signal, to be analyzed and which comprise a display screen on which information about the received signal is displayed for the user of the test instrument. For obtaining data or information about the received signal, the test instruments further comprise a data processing unit which is inter alia used for processing and analyzing the received signals.
Usually, the data processing unit provides more data than can be displayed on one screen, in particular in a graphic displayed on the display screen. Accordingly, such measurement instruments have mechanisms allowing the user to adjust the information or data to be displayed on the display screen. These mechanisms are typically provided by buttons which have to be pressed by the user.
Particularly, hand-held test instruments for measuring and/or analyzing signals such as hand-held signal/spectrum analyzers, hand-held network analyzers, hand-held oscilloscopes or hand-held directional finding units use a lot of buttons as mechanisms to control which data is displayed on the display screen and how the data is displayed on the display screen.
However, such portable test instruments may be used under harsh conditions, for instance under adverse lighting conditions, which make it difficult to recognize which button has to be pressed for displaying the required information/data and/or for executing the desired operation which is related to a certain button.
Other (hand-held) test instruments use a graphical user interface displaying icons which have to be pressed for executing the desired command. However, depending on the design of the icons, the control is more or less intuitive.
Therefore, a lot of experience is required to find the correct button and/or to understand the meaning of each icon.
Therefore, currently available hand-held test instruments do not provide an intuitive control.